1. Field of the Invention
This invention relates to an image recording apparatus for recording images on a photosensitive material mounted peripherally of a drum.
2. Description of the Related Art
In an image recording apparatus for recording images by emitting laser light to a photosensitive material and vaporizing components of the photosensitive material as a gas from the surface of the photosensitive material, the gas generated from the photosensitive material enters the exposure head and contaminates the interior of the exposure head. Thus, an image recording apparatus with a gas suction device has been proposed as described in Japanese Patent No. 2886087.
It is well known that such an image recording apparatus can achieve an improved gas suction efficiency with a gas suction opening disposed adjacent the surface of the photosensitive material.
However, where such an apparatus uses a clamp mechanism for clamping an end of a printing plate, as a device for mounting the printing plate peripherally of a rotatable drum, it is difficult to place the suction opening adjacent the drum since the clamp mechanism has a certain size. Then, a large volume of flow is required to suck the gas. In other words, a suction volume per unit time must be increased. Thus, an image recording apparatus with an improved gas suction efficiency has also been proposed as described in Japanese Unexamined Patent Publication 2000-56400, in which the gas generated from the surface of a printing plate is sucked while being separated from the printing plate by another gas directed to the drum. Actually, however, the gas generated from the photosensitive material is not sucked completely or efficiently. Consequently, when images are recorded on the photosensitive material continuously for a long time, the gas generated from the photosensitive material inevitably enters the exposure head to contaminate the interior of the exposure head.